The following are the braod-based objectives of the proposed investigation: 1. To isolate stratified squamous epithelial basal lamina (SSE-BL) from oral mucosa and skin and to subsequently purify its individual components. This will be accomplished by solubilizing the lamina in a variety of denaturing and reducing agents and then fractionating the soluble components by a combination of gel filtration, ion exchange and affinity chromatography. 2. To elucidate the major chemical and physicochemical characteristics of the purified proteins. Chemical characteristics to be determined are amino acid composition by automated analysis, carbohydrate composition by gas-liquid chromatography and terminal amino acid analysis by specific chemical reaction. 3. To immunologically characterize BL from bovine oral mucosa and human skin by immunohistochemical, immunocytochemical, immunochemical and immunoelectrophoretic techniques. Immunological identity and cross-reaction with basal laminae from homologous and heterologous tissues and species will be determined. Ultrastructural localization of the antigenic determinants of BL will be established using immuno-electron microscopy with peroxidase and ferritin conjugated antibody. BL synthesis in healing wounds of the oral mucosa and skin will be studied by fluorescent antibody and immuno-electron microscopic techniques. 4. To study BL changes in a group of diseases which manifest their pathology in the mucosa of the oral cavity, including: squamous cell carcinoma, bullous and benign mucous membrane pemphigoid and adenocystic carcinoma.